Ok, it may interest someone, in my case I was using a black background and the “Leave a Reply” text was unreadeble, my solution was invert colors by changing the php comments of Jetpack.
Edit the file jetpack/modules/comments/comments.php
Find the following:
var $default_color_scheme = 'light';
Change to:
var $default_color_scheme = 'dark';
It may be useful for someone but will not help the width and height problems for someothers.
Hope it helps.
